This application makes reference to, incorporates the same herein, and claims all benefits accruing under 35 U.S.C. xc2xa7119 from an application for MICROWAVE OVEN AND METHOD OF CONTROLLING FOR POWER SAVING MODE THEREOF earlier filed in the Korean Industrial Property Office on Mar. 9, 2001 and there duly assigned Serial No. 12340/2001 by that Office.
1. Field of the Invention
The present invention relates in general to a microwave oven and a method for controlling a power saving mode thereof, and more particularly, a microwave oven and a method for controlling a power saving mode thereof, with a power saving function automatically and manually operable.
2. Description of the Related Art
Generally, a microwave oven includes a cooking chamber, a magnetron heating food in the cooking chamber, a component chamber accommodating a high voltage transformer (HVT) and a low voltage transformer (LVT), and a lamp provided at one side of the cooking chamber, illuminating the inside of the cooking chamber.
In order to operate the magnetron, the transformer must generate a very high frequency voltage because the magnetron is operated by the high frequency voltage. Consequently, the transformer generating the high frequency voltage consumes a large amount of power.
Further, in a standby mode, that is, during the time the magnetron does not operate, if the microwave oven is connected to an electric power source, electric power is supplied to internal components such as a display part indicating a cooking state and time, a diode, a sensor, etc. Thus, electric power is unnecessarily wasted.
Most of lamps illuminating the cooking chamber of the microwave oven are turned on during the cooking. However, commonly, a user does not look at the cooking part, and therefore the lamp may waste electric power unnecessarily.
Accordingly, a microwave oven that has a power saving function lowering a power consumption has been developed and is already on the market. The power saving function is performed by canceling an indication of the display part to indicate when the magnetron does not operate or by turning off the lamp of the cooking chamber during operation of the magnetron, so as to prevent the microwave oven from wasting electric power.
However, in the conventional microwave oven equipped with the power saving function, there is the inconvenience that the power saving function may be set up by only manual manipulation with a power saving button.
Accordingly, the present invention has been made keeping in mind the above-described shortcoming and user""s need, and an object of the present invention is to provide a microwave oven and a method for controlling a power saving mode thereof, which can perform and suspend a power saving mode automatically according as a door is closed and opened.
The above and other objects of the present invention may be accomplished by the provision of a microwave oven including a power supplying part, a main body forming a cooking chamber, a door opening and closing the cooking chamber,.a magnetron performing cooking, and high and low voltage generating parts connected to the power supplying part in parallel and supplying voltage to the magnetron, further including: a door switch installed at the junction on which electric lines of the high and low voltage generating parts and the power supplying part meet one another, operating depending on opening and closing the door and selectively connecting the power supplying part with the low or high voltage generating part; a power saving switch provided on a branch line in front of the door switch, controlling a connection between the power supplying part and the low voltage generating part; and a controller switching off the power saving switch and cutting off electric power supplied to the low voltage generating part when a predetermined time elapses after the magnetron stops operating in the case that the door is closed.
A door switching part includes a common contact point connected to the power supplying part, a first contact point connected to the low voltage generating part, and a second contact point connected to the high voltage generating part.
Preferably, the microwave oven further includes a power saving selection part selecting the power saving mode and a normal mode, a lamp illuminating the inside of the cooking chamber, and a lamp switch controlling electric power supplied to the lamp from the power supplying part so as to turn on/off the lamp; and wherein the controller switches off the lamp switch in the case that the magnetron is operating at the power saving mode.
The controller switches off the power saving switch and the lamp switch in the case that the magnetron is not operating at the power saving mode, so as to perform the power saving function.
Effectively, the controller returns the power saving mode into the normal mode when the door is opened.
Effectively, the controller switches on the power saving switch when the magnetron operates again.
According to another aspect of the present invention, the above and other objects may be also achieved by the provision of a method for controlling a power saving mode of a microwave oven including the steps of: determining whether or not the power saving mode is selected; and cutting off electric power supplied to the lamp during operation of the magnetron at the power saving mode, and cutting off electric power supplied to the low voltage generating part when a predetermined time elapses after the magnetron stops operating at a normal mode.
Herein, the method further includes the step of re-supplying electric power to the low voltage generating part when the door is opened.